pull-requests: log a mismatch of name changed during a display of a PR.

If long-living PR was altered that the names of repo doesn't match anymore, we'll show a warning instead of silent 404.

rhodecode/apps/repository/views/repo_pull_requests.py

@@ -351,6 +351,8 b' class RepoPullRequestsView(RepoAppView, '
         # pull_requests repo_name we opened it against
         # ie. target_repo must match
         if self.db_repo_name != pull_request_at_ver.target_repo.repo_name:
+            log.warning('Mismatch between the current repo: %s, and target %s',
+                        self.db_repo_name, pull_request_at_ver.target_repo.repo_name)
             raise HTTPNotFound()
 
         c.shadow_clone_url = PullRequestModel().get_shadow_clone_url(